rw := httptest.NewRecorder()
	trw := &trackingResponseWriter{ResponseWriter: rw}

	if headersAlreadyWritten(trw) {
		t.Fatal("headers have not been written yet")
	}

	trw.WriteHeader(123)
	if !headersAlreadyWritten(trw) {
		t.Fatal("headers were written")
	}
}

func TestHeadersAlreadyWrittenWrapped(t *testing.T) {
	rw := httptest.NewRecorder()

			objInfo:         objInfo,
			expectedFlag:    true,
			expectedCode:    304,
		},
	}
	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			recorder := httptest.NewRecorder()
			request := httptest.NewRequest(http.MethodHead, "/bucket/a", bytes.NewReader([]byte{}))
			request.Header.Set(xhttp.IfNoneMatch, tc.ifNoneMatch)
			request.Header.Set(xhttp.IfModifiedSince, tc.ifModifiedSince)

				"test1": {}, "test2": {}, "test3": {}, "test4": {},
			},
		},
	}

	for _, testCase := range testCases {
		t.Run(testCase.name, func(t *testing.T) {
			rec := httptest.NewRecorder()
			req := httptest.NewRequest("GET", "/test", nil)
			req.Header = testCase.headers

			opts, _ := getAndValidateAttributesOpts(ctx, rec, req, bucket, "testobject")

			sum := sha256.Sum256(body)
			req.Header.Set("X-Amz-Content-Sha256", hex.EncodeToString(sum[:]))
			req = signer.SignV4(*req, credentials.AccessKey, credentials.SecretKey, "", "us-east-1")

			rec := httptest.NewRecorder()
			api := objectAPIHandlers{
				ObjectAPI: func() ObjectLayer {
					return obj
				},
			}
			api.GetObjectLambdaHandler(rec, req)

			res := rec.Result()
			defer res.Body.Close()

			if chksm.Type.FullObjectRequested() {
				m[xhttp.AmzChecksumType] = xhttp.AmzChecksumTypeFullObject
			} else {
				m[xhttp.AmzChecksumType] = xhttp.AmzChecksumTypeComposite
			}

			w := httptest.NewRecorder()
			AddChecksumHeader(w, m)
			gotChksm, err := GetContentChecksum(w.Result().Header)
			if tt.wantErr {
				if err == nil {
					t.Fatalf("Expected error for %s, got none", tt.name)
				}
				return
			}

	var okHandler http.HandlerFunc = func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
	}
	for i, test := range sseTLSHandlerTests {
		globalIsTLS = test.IsTLS

		w := httptest.NewRecorder()
		r := new(http.Request)
		r.Header = test.Header
		r.URL = test.URL

		h := setRequestValidityMiddleware(okHandler)
		h.ServeHTTP(w, r)

		switch {